a.backToTop {
	width: 30px;
	height: 45px;
	position: fixed;
	bottom: 20px;   /*页边距*/
	right: 20px; /*页边距*/
	background:url(../image/top.gif) no-repeat -20px 1px;
	display: none;
	border: 1px solid #CCC;
}
a.backToTop:hover {
	background:url(../image/top.gif) no-repeat -20px 1px;
	background-color:#333;
}